Let me play devil’s advocate. I’m sure that the founders thought that federal law would be so limited to the functions of the national government that no law would be in violation of both state and federal law.
And further, I don’t think the drafters of the 14th Amendment thought it would be so broad either, say, to apply to a state like California that is fully committed to racial equality that the Civil Rights Laws would apply to their police officers arresting a person.
Again I thank you for the cites. You have shown that I need to do more research on federal civil rights law. I always read that law to require a racial hook to bring it under federal purview. And IIRC, a big thing about the Rodney King case was a statement made by one of the officers (over the radio of all things) about how there were so many black people out that night that it looked like a scene from Gorillas In the Mist or some other horrifically racist comment that provided the hook for a federal prosecution.
I find the logic of the decisions that you cite unpersuasive but recognize their controlling authority. The very idea of a “custom” means that the state itself has washed its hands of it by not enacting it into law. The state has no means to enforce a custom because any defense attorney could cite to the lack of a law as reason why this custom cannot be enforced against his client. But again, thank you very much for pointing me against what I stated which is wrong.